Installing a five speed transmission into a classic muscle car could not be any easier these days. Not only is it easy but there are numerous choices to be had.
Many of the five speed transmissions found in late model Fords (late model being those produced in the past 35 years) can be used in a swap with little modification. There are several good five speed transmissions to choose from. The Borg Warner/TREMEC T5, TREMEC 3550, and TKO, and the TKO 500/600. T-45 transmissions found in 1996-99 4.6L Mustangs are limited to just that 4.6L as the bolt pattern is completely different than that of Windsor blocks. 4.6L motors are not limited to the T-45 as there is a bell to install a TREMEC behind a 4.6L mod motor. More on that later. All of the transmissions offer a 5th gear over-drive to reduce engine rpm and for improved mileage while weighting less than their automatic or four speed counterparts.
There are three ways to approach a five speed swap:
- Use an early 3 or 4 speed bell housing with an adapter plate allows an easy T5 swap,
- Use a late T5 or TREMEC TKO bell housing, which allows each transmission to be bolted directly to the bellhousing without the use of adapters or spacers,
- Use an after market scatter shield, which adds additional safety and sometimes the only bellhousing available for an application.
Which conversion choice you choose depends on what parts you are starting with and how you set up the clutch linkage.